Somewhere beneath the spinifex and dry creek beds of north-west Queensland, a pipe just thirty centimetres wide is pushing zinc toward the ocean. It runs 304 kilometres, buried out of sight, from the old open pit at Lawn Hill to the port of Karumba on the Gulf of Carpentaria. A single pump station at the mine end pressurises the line and shoots batches of metal slurry across the savanna - the longest single-pump-station slurry pipeline anywhere in the world. Century is mostly a quiet place now, its giant pit filling with water, but the metal keeps flowing.
The story begins with a discovery. In 1990, geologists working for CRA Limited identified a massive zinc deposit in the country around Lawn Hill, 250 kilometres north-west of Mount Isa. It was enormous - one of the great zinc-lead-silver orebodies of the world. But finding it and digging it were separated by nearly a decade of negotiation, financing and construction. Development began in 1997. Production from the open pit started in 1999, ten years almost to the day after the orebody was confirmed. For the next sixteen years, Century ran as Australia's largest open-cut zinc mine, producing on average 475,000 tonnes of zinc concentrate and 50,000 tonnes of lead concentrate every year, ranking it among the biggest zinc operations on the planet.
The ore sat in the traditional country of the Waanyi people, and that fact shaped everything. In May 1997, before the first blast, the Gulf Communities Agreement was signed between the Waanyi, Mingginda, Gkuthaarn and Kukatj native title groups, the State of Queensland and the mining company. It was the first multi-party native title agreement of its kind in Queensland - a landmark document covering land use, benefit-sharing, cultural heritage protection, and commitments to education, training and employment for Aboriginal people. The agreement was not perfect, and its legacy has been debated by the communities who signed it. But it broke ground that later mining deals across Australia would build on, and it placed the people of this country at the negotiating table rather than outside the gate.
Century's most remarkable feature was never the pit - it was the line that carried the metal away. Rather than truck concentrate across hundreds of kilometres of unsealed road, the operation mixed it with water into a slurry and pumped it underground. The pipeline, around thirty centimetres in diameter and buried for protection, drives batches of concentrate the full 304 kilometres to Karumba, where the slurry is dewatered and the dried concentrate loaded onto barges. When mining finished, the last of the ore was processed in early 2016, and the final shipment of zinc left Karumba in late January that year. The pit fell silent. The pipe did not stay that way for long.
Sixteen years of milling had left behind a vast field of tailings - the fine sand discarded after the valuable metal was extracted. Old processing left a lot of zinc still locked inside it. In 2018, New Century Resources restarted the operation with a different idea: instead of digging new rock, reprocess the waste. The tailings hold a proven reserve of 77.3 million tonnes grading 3.1 percent zinc-equivalent, enough for more than two million tonnes of contained zinc. The refurbished pipeline came back to life, pushing concentrate to the coast once again. In 2023 the project passed to Sibanye-Stillwater. Century now lives a second life, recovering metal from what an earlier era threw away.
Century Mine sits at 18.73 degrees south, 138.61 degrees east, in the Gulf hinterland of north-west Queensland, 250 km north-west of Mount Isa. From altitude the flooded open pit and the pale tailings storage areas stand out sharply against the red-and-green savanna; the Lawn Hill gorge country lies just to the north. The climate is tropical semi-arid, with a short wet season from December to March and clear, hot, dry skies the rest of the year - April to November offers the best visibility. The nearest controlled field is Mount Isa Airport (ICAO YBMA) to the south-east; Burketown (YBKT) lies north-east toward the coast, and the port of Karumba (YKMB), the far end of the slurry pipeline, sits on the Gulf shore.